U.S. Pat. No. 4,616,640 for a "Birth Control Method and Device Employing Electric Forces" - issued Oct. 14, 1986 - Steven Kaali, Peter M. Schwolsky and Joseph W. Porter -inventors discloses a novel method and device using electric field forces within or about the cervical canal of a female mammal for acting on sperm and preventing migration of the male sperm through the cervical canal into the uterine cavity where it might fertilize an egg.
U.S. Pat. No. 4,770,167 for an "Electrical, Generally Rounded Resilient, Canopy-Like Contraceptive Devices" - issued Sept. 13, 1988 to Steven Kaali and Peter M. Schwolsky - inventors discloses and claims electrified contraceptive devices of the diaphragm and/or cervical cap type wherein electrical forces generated within the device augment the contraceptive action of either a diaphragm or a cervical cap.
U.S. patent application Ser. No. 141,132 filed Jan. 6, 1988 for an "Electrified Vaginal Ring", Steven Kaali and Peter M. Schwolsky, inventors, discloses and claims an electrified vaginal ring for use as a contraceptive device for birth control purposes.